Ingredients below are per pound of milled russet potato. Start with approximately four medium russet potatoes to make one pound of milled potato.
Wash and prick the potatoes with a fork several times. Bake the potatoes in 425 degree oven. When potatoes are tender, remove from oven, and cool for ten minutes; slice in half. Remove the potato pulp from the skin and place into a food mill or potato ricer. Pass the potatoes through the mill, and then weigh the milled potatoes. Place approximately one pound of milled potatoes into a bowl, and then add the flour to gently incorporate; the mixture will become crumbly. Whisk the egg yolks, and then add whisked yolks, parmesan, nutmeg, and salt to the potato-flour mixture, and again gently incorporate. Knead the dough until it forms a loose mass. Incorporate more flour if the dough seems wet or sticky.
When the dough has come together and all the ingredients are incorporated, shape into an oval and cover with a damp cloth. Line a sheet tray with parchment paper. With a pastry cutter, cut a small (approximately 2”x2”) piece off of the dough and sprinkle with flour. Roll into a cylindrical piece, approximately one-half inch diameter, using additional flour as needed to keep the cylinder from sticking. Using the cutter cut ½” pieces and then roll gnocchi gently on a fork or grooved gnocchi board and place on the parchment lined sheet tray. Place tray in freezer until gnocchi are frozen, then move to plastic freezer bag, and return to freezer until ready to cook. When ready to use, remove from freezer and let stand at room temperature for five minutes. Gnocchi will keep frozen for up to a month.
One pound of dough will make approximately 100 half-inch gnocchi, or 4 generous portions as a main course.